Thread tensioning apparatus for twisting spindles



Nov. 4, 1958 V w. LENK 2,859,001

THREAD TENSIONING APPARATUS FOR TWISTING SPINDLES Filed Nov. 8. 1955 2 A: 16 W H. F-.\\\\\ ATTORNEY THREAD TENSIONING APPARATUS FOR TWISTING SPINDLES Walter Lenk, Remscheid-Lennep, Germany, assignor to Barmer Maschinenfabrik Aktiengesellschaft, Wuppertal-Oberbarmen, Germany Application November 8, 1955, Serial No. 545,610 Claims priority, application Germany November 8, 1954 4 Claims. (Cl. 242-447 This invention relates to thread tensioning apparatus for twisting spindles, especially multiple thread twister spindles. More particularly, the invention relates to thread tensioning apparatus mountable on a bobbin and including a guide member having a bore or opening therethrough and a tensioning wire mountable on the guide member for tensioning thread or yarn unwinding from the bobbin and for rotation during the unwinding.

This application is a continuation-in-part of and constitutes a further improvement over my copending patent application, Serial No. 457,037, filed September 20, 1954, now Patent No. 2,762,583, granted September 11, 1956, the disclosure of which is incorporated herein and made a part hereof by reference as fully as if set forth herein I in its entirety.

Thread or yarn tensioning appliances for twisting spindles have been proposed which, however, have suffered from several drawbacks. In the above-identified application, new and improved thread tensioning apparatus which overcomes the prior difficulties is described. Yarn tensioning apparatus for twisting spindles, especially of the .cable type, is disclosed which insures correct unwinding or drawing of the thread to be twisted from the bobbin, imparting a small and uniform tension to the thread due to its high sensitivity.

In the apparatus, a guide member, also referred to as a yarn drawing or winding member, is provided which is mountable on the bobbin in fixed position. The guide member has an axial bore or thread passage or opening therethrough, extending from the outer or upper end of the guide member and communicating with the chamber within the tubular bobbin. A tensioning wire in the form of a hairpin or the like is also provided, and it is rotatably mounted on the guide member with one leg in the bore and the other outside of the guide member for rotation therearound while engaging the thread. The tensioning wire serves to impart tension to and guide the thread i which is being unwound from the bobbin, which may be, for example, a cop. The thread being unwound next passes through the bore or thread passage in the guide member and then through the chamber of the bobbin to the twisting spindles. The twisting spindles exert tension on the thread which unwinds it from the bobbin. As the thread unwinds, it rotates the tensioning wire.

In the apparatus, one leg of the tensioning wire is inserted in the bore of the guide member and is rotatable therein with clearance for passage of the thread. The remaining leg of the wire is supported on the outer surface of the guide member, on a bulge thereon, for rotation on the bulge. An inwardly bent portion of the outer leg is located in an annular peripheral groove or channel on the guide member, tomaintain the wire in position during operation and when threading the apparatus. The bulge may be adjacent or form .a side wall of the groove, and it supports the wire above the outer end or head of the guide member and clear of the thread passing therearound. The outer leg of the tensioning wire'has a thread United. States Patent With lower thread tension from the twisting spindle, the

outer leg of the tensioning wire lags behind the point of separation of the thread from the bobbin a certain distance, and there is then a thread reserve for a subsequent increase in tension from the spindle. With greater thread tension, there is less lag, and when tension from the spindle decreases, the wire lags more to take up. the slack. These effects impart to the thread a uniform small tension which results in the even supply of thread to the twisting spindles.

The =above-described bulge also exerts a braking effect on the rotating wire which produces corresponding tension on the thread. The degree of tension may also be varied by varying the weight of the tensioning wire, by affixing a weight to the wire, by causing a magnet to act on the wire, and in other ways.

The construction illustrated in the above application has proven to be very useful in practice. In certain cases, for example when the twisted thread breaks in the balloon, after passage through the spindle bore and after leaving the storage disc, which may occur because of eX- cessive tension, it is also of considerable importance to.

tion in the operation, and it is desirable to prevent further thread removal so that the broken thread .'ends can be quickly tied together for thecontinuation of operation,

and to conserve thread.

It is, therefore, an object of the present invention to provide a new and improved thread tensioning apparatus which arrests the removal of thread from the bobbin when a thread stoppage occurs, due to breaking or jamming, for example.

Another object is to provide an apparatus having means for stopping the rotation of the tensioning wire in the event of a thread stoppage, to prevent further removal of thread from the bobbin.

A particular object is to provide an apparatus having magnetic means for stopping the rotation of the tensioning wire.

A further object is to provide an apparatus having magnetic stopping means which also exert a braking action on the tensioning wire at operating thread tension.

A more particular object is to provide apparatus having magnetic stopping means which take efiect automatically on reduction of thread tension from the operating tension, particularly, due to the resulting change in position of the outer rotating leg of the tensioning wire.

An additional object is to provide a simple, reliable and economical construction for stopping the tensioning wire and thus preventing further removal of thread from the bobbin when a stoppage occurs. These and other objects, advantages and functions of the invention will be apparent on reference to the'specification and to the attached drawings, in which like parts are identified by like reference characters in each of the views, and in illustrating the position of the parts in normal operation at operating thread tension;

Fig. 2 is a view like Fig. l but illustrating the location of the parts when the thread tension is reduced from operating tension, as when the thread breaks, and

Fig. 3 is a cross-sectional view taken on line 3-3 of Fig.2.

As-noted above, the copending application describes a construction which may include a magnet arranged for exerting a braking effect on the rotating tensioning wire, to vary the degree of tension exerted on the thread by the wire. In the present invention, magnetic means are also employed to stop the rotation of the wire when thread tension is reduced from the operating tension especially when thread is broken in balloon. The invention thus comprises a thread tensioning apparatus for twisting spindles which includes a longitudinally bored guide member mountable on a bobbin, a hairpin-like tensioning wire rotatably mountable on the guide member, one leg of the wire being rotatable in the bore of the guide member, the remaining leg of the wire being rotatable about the guide member, a thread guide on the remaining leg, and associated magnetic means for stopping rotation of the wire on reduction of thread tension.

The magnetic means are preferably provided in the form of a magnet mounted on the guide member with' its pole arranged or positioned for permitting rotation of the wire at operating thread tension and for stopping the rotation on reduction of thread tension. It is further preferred that the pole of the magnet be located for exerting a braking action on the wire at operating thread tension. In a more specific preferred embodiment, all or, preferably, part of the magnet extends short of the circle described by the Wire when rotating at operating thread tension and extends about to the circle described by the wire when rotating at reduced thread tension due to thread stoppage.

Referring to the drawings, a bobbin spool or tube 1 is illustrated in Fig. 1 with a sonically-shaped guide member, or yarn winding member 2 fixedly mounted thereon. The guide member is provided with an axial longitudinal vertically extending bore or thread passage 3 extending therethrough and communicating with the interior or the chamber of the bobbin 1. At the outer, upper or head end of the guide member 2, a smooth annular protective collar or cap 4 is secured and forms a part of the guide member. The collar provides a mouth 5 at the end of the guide member and provides a rounded lip thereon. The collar is preferably formed of an abrasion-resistant material, such as glazed ceramic material, hard chromium plated and polished steel, or the like, to permit the thread 6 to slide over the lip easily and to reduce wear. The guide member 2 also includes an intermediate annular collar 7 mounted on the neck 8 of the guide member, and it is likewise preferably formed of an abrasionresistant material The remainder of'the guide member maybe constructed of cheaper, less abrasion-resistant material.

A hairpin-like tensioning wire 9 or the like is rotatably mounted on the guide member 2. The wire is preferably a single continuous piece, and includes a substantially straight-inner leg 10 joined by a reverse bend 11 to an outer guide leg 12. The straight leg 10 is positioned in the bore 3 of the guide member 2 with suflicient space or clearance remaining therein for the leg to rotate and for the thread to pass freely through the bore. The outer leg 12 is rotatably seated in a smooth, peripheral annular groove or channel 13 on the guide member 2 and on the lower or inner sidewall thereof formed by the shoulder or bulge 7. The wire 9 is thereby supported with its reverse bend 11 and the remainder of the wire closely adjacent while spaced from or out of contact with the lip formed by the collar 4, where the thread '6 passes around the collar, preventing pinching of the thread.

The outer leg 12 is formed or bent to provide a thread guide, eyelet, loop'or bend 14 at the free end thereof. The outer leg is also provided with an inwardly bent portion 15 which rests in the groove 13 and on the shoulder 7, supporting the wire member 9 as aforesaid. The wire is resilient metal, and the legs 10 and 12 are spread to mount the wire, after which the bent portion 15 springs into position in the groove 13. The groove holds the wire so that it will not be removed when the threading wire is inserted or during operation.

In the embodiment shown, the groove 13 is closely adjacent the outer or upper end of the guide member 2 and in close proximity to the axis of the bore 3. The groove 13 is preferably formed by joining a protective collar, such as 4, to the body 16 of the guide member 2 at the outer end of its neck 8 and also by joining a protective collar such as 7 to the body around the neck, intermediate the outer and inner ends of the neck. However, the guide member 2 might also be made in one piece, from a thermoplastic material, for example, or it may be machined from a solid piece.

In the operation of the apparatus, as in the above copending application, the thread 6 being supplied to the twisting spindles is unwound from the bobbin 1, passes through the thread guide 14 and over the protective collar 4 on the head of the guide member, and then passes through the axial bore 3 and through the interior of the bobbin 1 to the twisting spindle. During this operation, the tension exerted from the twisting spindle causes the thread to unwind around the bobbin, which in turn causes the thread guide 14 and the tensioning wire 9 to rotate. Due to the speedof rotation and the centrifugal force, the outer leg 12 is extended or pulled away from the guide member 2 as illustrated in Fig. l and rotates in a correspondingly wide circle. When thread tension decreases below the operating'tension due to a stoppage, the outer leg 12 of the wire returns to a position closer to the guide member somewhat as illustrated in Fig. 2 where, however, it continues to rotate as long as thread is being removed from the bobbin, as in the aforementioned manner, due to friction in the spindle bore or on the storage disc, and the continued movement of the wire is assisted by its momentum.

In the present invention, magnetic means are provided for stopping or holding the wire against further movement when the thread tension decreases below the operating tension. In the illustrative embodiment, a permanent magnet 17 is mounted on the neck 8 of the guide member 2, immediately beneath the protective collar 7. The magnet may be adjustably and removably mounted. The magnet illustrated is ring-shaped, and it'may also be in another form or shape, such as U-shaped, bar-shaped or otherwise. The magnet preferably has a projecting or protruding nose-like arm, ridge or extension 18 which extendslaterally towards the outer leg 12 of the tensioning wire. The magnet is protected and shielded by the non-magnetic shoulder or collar 7.

The magnet 17, and particularly the projecting portion or projection 18 comprising a pole of the magnet, is positioned or arranged to permit the leg 12 of the wire to rotate at operating thread tension, when the opposed portion 19 of the outer leg below the bent portion 15 is extended or spaced laterally as in Fig. 1. Thus, the opposed portion 19 of the outer leg is outside of the zone of strong magnetic attraction, so that the leg may rotate normally. The spacing between the projecting pole 18 and the opposed leg portion 19 may, however, be such as to provide a braking action on the wire, increasing the tension exerted on the thread by the wire.

The magnet 17 and the projecting pole 18 are also positioned for stopping the rotation of the wire on reduction of thread tension. Thus, the projecting pole 18 extends about to the circle described by the opposed portion 19 of the leg 12 of the wire when the wire is rotating at reduced thread tension due to thread stoppage as by breaking or jamming. The opposed portion 19 is then located in the zone of strong magnetic attraction, where the force of attraction is greater than the forces which tend to keep the wire rotating, and the wire is drawn to the magnet and rotation ceases. This holds the thread against further removal, so that balling or tangling is avoided, the broken thread ends can be tied together quickly, and operation can be resumed rapidly and Without difiiculties.

There is thus provided by the invention a new and improved thread tensioning apparatus which is especially useful for stopping rotation of the tensioning wire and, consequently, further removal of thread from the bobbin when a stoppage occurs. In particular, a magnetic pole is arranged with the tensioning wire so that it exerts at most a continuous braking action when the wire is rotating under operating thread tension, the wire being kept out of the strong magnetic field because the centrifugal force and the mass energy of the rotating leg are greater than the magnetic attraction. At the same time, the magnetic pole is arranged so that the tensioning wire enters the strong magnetic zone when thread tension decreases, where the magnetic force exceeds the other forces acting on the wire and stops the Wire. The apparatus functions automatically and very eifectivcly in a simple and reliable manner, and it reduces lost time and conserves thread in operation.

The invention is hereby claimed as follows:

1. Thread tensioning apparatus for twisting spindles comprising a longitudinally bored guide member mountable on a bobbin, a hairpin-like tensioning wire rotatably mountable on said guide member, one leg of said Wire being rotatable in the bore of said guide member, the remaining leg of said wire being rotatable about said guide member, a thread guide on said remaining leg, and a magnet on said guide member with its pole extending short of the circle described by said wire when rotating at operating thread tension and extending about the circle de scribed by said wire when rotating at reduced thread tension due to thread stoppage.

2. Apparatus as defined in claim 1 wherein said pole is arranged for exerting braking action on said wire at operating thread tension.

3. Apparatus as defined in claim 1 wherein said pole comprises a projecting portion of said magnet.

4. Thread tensioning apparatus for twisting spindles comprising a longitudinally bored guide member mountable on a bobbin, a hairpin-like tensioning wire rotatably mountable on said guide member, one leg of said wire being rotatable in the bore of said guide member, the remaining leg of said wire being rotatable about said guide member, a thread guide on said remaining leg, and a magnet on said guide member with its pole arranged with said remaining leg for permitting rotation of said wire at operating thread tension and for attracting said remaining leg to the pole and securing it against rotation on reduction of thread tension, said magnet being positioned on said guide member beneath a wire supporting collar thereon constructed of non-magnetic abrasion-resistant material.

References Cited in the file of this patent UNITED STATES PATENTS 2,762,583 Lenk Sept. 11, 1956 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 2,859,001 November 4, 1958 Walter Lenk It is hereby certified that error appears in the-printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 6, line 4, after "extending about" insert to Signed and sealed this 24th day of March 1959.

( SEAL) Attest:

KARL H. AXLINE ROBERT C. WATSON Attesting Oflicer Commissioner of Patents 

